Attempted Generation of the Potentially Aromatic 6,7-Diphenyldibenzo[<i>e,g</i>][1,4]diazocine Dianion Leads with Profound Rearrangement to the Isomeric <i>N</i>-(2-Amino-1,2-diphenylethenyl)carbazole Dianions

The attempted generation of the potentially aromatic 6,7-diphenyldibenzo[e,g][1,4]diazocine dianion from sodium in THF leads with profound rearrangement to the isomeric N-(2-amino-1,2-diphenylethenyl)carbazole dianions and, after hydrolysis, to a 55:45 mixture of Z- and E-isomers of N-(2-amino-1,2-diphenylethenyl)carbazoles. These isomers were separated and their individual structures determined by X-ray diffraction. Since treatment of the starting diazocine first with tert-butyllithium and then with water also yielded the same Z- and E-isomeric mixture, electron transfer reduction is clearly involved.